XL1201 Power Consumption

I was asked how much power is used by the XL1201. Here are a few data points...

  • XL1201 with only SCSI2SD: 222-233W
  • Console: 106W

With the XL1201 sitting idle it takes the same amount as calculating (fib 36), so apparently the CPU is running at a constant speed at all times.

When the console goes into sleep mode (after 20 minutes by default), power usage doesn't appreciably drop.

  • Console sleep mode: 105W

With the XL1201 running a 15,000 RPM Seagate Cheetah X15 drive (ST318451LW), it doesn't really take all that much more power.

  • XL1201 with 15k drive and SCSI2SD: 238W
  • Total: 343W


Where I live, electricity isn't particularly cheap. We have two variable charges:

  • Supply: 6.1247¢/kWh
  • Delivery: 10.8441¢/kWh
  • Sub-total: 16.9688¢/kWh

But there are also a basic fee, plus several taxes and charges so the actual supply and delivery charge only accounts for about 71% of the electric bill. (So, add about 41% to get the total bill.)

  • Total: about 24¢/kWh (based upon a bill with 449 kWh used)
  • XL1201 operating cost: $0.24 x 0.343 = $0.082/hour
  • XL1201 cost per day: about $2

Douglas Fields

Writing LISP and Haskell since 1990